Investigation into the Mechanical Properties and Fracture Behavior of A356 Aluminum Alloy-Based ZrO2-Particle-Reinforced Metal-Matrix Composites

In the present study, an investigation has been carried out into the influence of ZrO2 content and casting temperature on the mechanical properties and fracture behavior of A356 Al/ZrO2 composites. A356 aluminum alloy matrix composites reinforced with 5, 10 and 15 vol.% ZrO2 were fabricated at 750, 850, and 95 0°C via the stir-casting method. Based on the results obtained, the optimum amount of reinforcement and casting temperature were determined by evaluating the density and mechanical properties of the composites through the use of hardness and tensile tests. The fracture surfaces of composite specimens were also studied to identify the main fracture mechanisms of the composites. The results obtained indicated that all samples fractured due to the interdendritic cracking of the matrix alloy. Reinforcing the Al matrix alloy with ZrO2 particles increased the hardness and ultimate tensile strength of the alloy to the maximum values of 70 BHN and 232 MPa, respectively. The best mechanical properties were obtained for the specimens with 15 vol.% of ZrO2 produced at 75 0°C.